Artificial leg



9 9 h 3 m a l d e .I n e t a P S W E R D N A W 2% 7 mm B 0 N ARTIFICIALLEG.

(Application filed Nov. 1, 1895.)

INVENTOR BY m, M

ATTORNEY.

(No Model) WITNESSES.

THE Nouns PETERS co. PHOTO-LYING" WASPHNGTDN. n. c.

WILLIAM ANDREWS, OF LOIVELL, MASSACHUSETTS.

ARTIFICIAL LEG.

SPECIFICATION forming part of Letters Patent No. 616,873, dated January3, 1899.

Application filed November 1, 1895. Serial No. 567,569. (No model.)

T0 at whom it may concern.-

Be it known that 1, WILLIAM ANDREWS, a citizen of the United States,residing at Lowell, in the county of Middlesex and Commonwealth oflllassachusetts have invented a certain new and useful Improvement inArtificial Legs, of which the following is a specification.

My invention relates to artificial legs, and comprises an improved corefor the foot, means of attaching the core to the shell or leg proper,means of giving a greater lightness and elasticity to the heel, andmeans of attaching the hamstring to the leg and thigh-piece to limit theforward motion of the leg with reference to the thigh.

In the accompanying drawings, Figure 1 is a side elevation of a legprovided with my improvements Fig. 2, a rear elevation of the same; Fig.3, a vertical section of the foot and lower part of the leg through thecenter of the heel and great toe Fig. l, a rear view of the plate towhich the hamstring is attached; Fig. 5, a vertical section of saidplate on the line 5 5 in Fig. at Fig. 6, an isometric view of parts oftoe-springs and envelop, the cords of the upper spring being exposed.

The lacer or thigh-piece A to receive the thigh and provided withbuttons at to engage a strap which in practice is passed over theshoulder of the wearer, the metallic hinge B, connecting saidthigh-piece to the shell or leg proper, C, and said shell are of theusual construction except as hereinafter stated.

The core D of the foot is of selected wood having a natural bend orcrook, such that the grain of the wood is as nearly as possible parallelwith the curved central line of the core from end to end thereof,whichmakes it almost impossible to break the core in use. The upper end ofthe core is reduced at (Z to form a tenon or stud which enters acorresponding hole or mortise o in the lower end of said shell 0, andthis hole or mortise 0 maybe continuous with the hollow or cavity 0 ofsaid shell, as shown in Fig.3. The tenon is retained in and preventedfrom turning in the shell G by glue and by one or more dowel-pins (1 Thecore D is provided with a shoulder (1 which is in contact with the lowerend of the shell; but the circumference of the core at said shoulder,including the shoulder, is slightly less than that of the lower end ofthe shell.

Over the core D is arranged an elastic covering E, of soft flexiblerubber or other suitable flexible plastic material, having the externalshape of the natural foot and having its external surface continuouswith that of the socket O, the top of said covering being of thethickness of the space between the outer edge of the shoulder d and theoutside of said socket.

Within the covering E is arranged a toespring F, similar to what isshown in my pending application, Serial No. 429,281, filed April 15,1392, in the respect that said spring extends from a point above thecore beyond the toe of said core and from a point below said core beyondthe toe of said core, and no claim is made herein to this peculiarity ofsaid spring; but the toe-spring shown herein, in addition to the cords farranged at intervals and extending lengthwise of said spring, has othercords f arranged at intervals transversely of the cords f and preferablyinterlaced with said cords f, all said cords being embedded in rubber,which becomes hard when vulcanized, and the interstices between saidcords form a spring, being large enough to allow them to be penetratedby the said rubber when in its plastic state before vulcanization, sothat said rubber is a continuous piece on both sides of and between allsaid cords. The additional cords f prevent the hard rubber from beingbroken between the cords fand said last-named cords from spreadingapart. The construction of the spring is best shown in Fig. 6. Thenumber of such springs F used will depend on the weight of the personand the strain to which the foot is likely to be subjected, a laborersartificial foot requiring more such springs than would be necessary inthe foot of a man who merely uses his foot in walking. Four springs Fare shown in Fig. 3, with a layer of soft rubber between each spring andthe next and another layer of soft rubber between the upper spring'andthe core-that is, all the springs F are embedded in the soft rubberof the envelop E.

Within the heel portion of the envelop E below the core is formed an'airspace or cell G, which serves to lighten the foot and to increase thespring action thereof and to yield when the foot is inclosed in a tightshoe, as a solid rubber heel could not do. The airspace G obviates thenecessity of an anklejoint by allowing the heel to compress and contractwhen the weight of the wearer is put upon the heel in walking.

The attaching-plates H II are substantially alike, the upper one IIbeing longer to give a greater bearing on the lacer or thigh-piece,which being of soft sheet material, as leather, does not afford as goodan opportunity for securing said upper plate as is oifered by the rigidwooden socket G, to which the lower plate II is fastened by screws it,while the upper plate is secured by rivets h. Each attaching plate is ofsheet metal, laterally curved to fit the thigh-piece or socket, as thecase may be, and is inverted with respect to the other, and each isoffset at 7L2 7& near its straight end or end nearest the otherattaching-plate to allow the lacing I or hamstring to pass between theoffset portion of such plate and the thigh-piece or socket, said lacingpass ing back and forth through holes 71* 7L5, with which said offsetportions respectively are provided, and being tied at the ends, as shownin Fig. 1, so that the greatest distance of the plates II II may belimited and the forward swing of the socket with reference to thethighpiece may be made to correspond to the action of the natural leg.The lacing I is preferably of rawhide.

To prevent wearing the clothing, the attaching plates. are covered withleather stitched at h at the edges, as indicated by dotted lines in Fig.4, and these edges of the leather allow of the upper plate II beingsecured to the thigh-piece by stitches as well as by rivets. The holesh" 7L5 are protected by eyelets 7L7, as shown in Fig. 4, to prevent saidplates from cutting the lacing.

I claim as my invention- 1. The combination of the core, an elasticcovering therefor of the external shape of the natural foot, and atoe-spring, arranged in said covering and extending from a point infront of said core above and below said core and consisting of cords,arranged at intervals in a layer and extending longitudinally andtransversely of said spring and embeddedin hard rubber, said hard rubbercovering said layer on both sides and filling the interstices betweensaid cords, as and for the purpose specified.

2. An artificial foot, consisting of an inelastic core and an elasticportion in the outline of the foot and inclosing said core, the heel ofsaid elastic portion having within it an air space or cell;substantially as set forth.

3. The combination of the lacing and the attaching-plates, arrangedwholly below the upper end of the socket and above the lower end of thethigh-piece and curved laterally to fit the thigh-piece and the socketand offset at their adjacent ends to leave spaces between said platesand said thigh-piece and socket, said plates being provided with eyeletsto receive said lacing, as and for the purpose specified.

In witness whereof I have signed this specification, in the presence oftwo attesting witnesses, this 28th day of October, A. D. 1895.

WILLIAM ANDREIVS.

\Vitn esses ALBERT M. Moons, JAMES JACQUES.

